Platelet-activating factor receptor and respiratory and metabolic responses to hypoxia and hypercapnia.

Abstract

Activation of the platelet-activating factor receptor (PAFR) regulates neural transmission. A PAFR blocker reduced the peak hypoxic (pHVR) but not hypercapnic ventilatory (HCVR) responses in rats [Am. J. Physiol. 275 (1998) R604]. To further examine the role of PAFR in respiratory control, genotype-verified PAFR -/- and PAFR +/+ adult male mice underwent hypoxic and hypercapnic challenges. HCVR was similar in the two groups (p-NS). However, pHVR was significantly reduced in PAFR -/- mice (38 +/- 13% baseline [S.D.]) compared to PAFR +/+ mice (78 +/- 16% baseline; P < 0.001, ANOVA), with reduced tidal volume recruitments during pHVR. In addition, hypoxic ventilatory depression was attenuated in PAFR -/- mice (P < 0.01), and was primarily due to attenuation of the time-dependent decreases in oxygen consumption during sustained hypoxia (P < 0.01). Thus, PAFR expression/function modulates components of the acute ventilatory and metabolic adaptations to hypoxia but not to hypercapnia. Imbalances in PAFR activity may lead to maladaptive regulation of the tightly controlled metabolic-ventilatory relationships during hypoxia.

• Authors: Stephen R Reeves, David Gozal
• Journal: Respiratory physiology & neurobiology (Respir Physiol Neurobiol) Vol. 141 Issue 1 Pg. 13-20 (Jul 12 2004) ISSN: 1569-9048 [Print] Netherlands
• PMID: 15234672 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Platelet Membrane Glycoproteins
• Receptors, G-Protein-Coupled
• platelet activating factor receptor

Topics

• Adaptation, Physiological
• Animals
• Female
• Hypercapnia (physiopathology)
• Hypoxia (physiopathology)
• Male
• Mice
• Mice, Inbred C57BL
• Mice, Transgenic
• Oxygen Consumption (physiology)
• Platelet Membrane Glycoproteins (deficiency, metabolism)
• Pulmonary Ventilation (physiology)
• Receptors, G-Protein-Coupled (deficiency, metabolism)
• Respiratory Mechanics (physiology)